# Understanding the Progression of Chronic Kidney Disease in Cats: From Pathophysiology to Emerging Biomarkers

## TL;DR

This paper reviews how chronic kidney disease in cats progresses and explores new biomarkers that can detect the disease earlier, allowing for better treatment and improved cat health.

## Contribution

The paper introduces emerging biomarkers for early detection of feline chronic kidney disease, enabling proactive veterinary management.

## Key findings

- Symmetric dimethylarginine and fibroblast growth factor-23 detect early metabolic and filtration changes in cats.
- Urinary biomarkers like cystatin B and retinol-binding protein indicate tubular injury in chronic kidney disease.
- A multi-parametric diagnostic approach using novel biomarkers improves early detection and monitoring of the disease.

## Abstract

Chronic kidney disease is one of the most common medical conditions in older cats, leading to a gradual and permanent loss of kidney function. Unfortunately, by the time a cat shows signs of illness or traditional blood tests detect a problem, a large portion of the kidneys may already be damaged. This review focuses on the mechanisms underlying disease progression and critically examines emerging biomarkers with the potential to detect renal dysfunction at earlier stages than currently available methods. By reviewing the latest scientific research, we highlight how these tools can help veterinarians detect the disease in its silent stages. Earlier identification allows not only earlier intervention but also more accurate monitoring of disease progression. This shift enables veterinarians to move from a reactive approach toward proactive management strategies, which may significantly extend survival time and improve the quality of life of aging feline patients.

Feline chronic kidney disease is a leading cause of mortality in geriatric cats, characterized by a progressive and irreversible loss of renal function. Despite its high prevalence, early diagnosis remains challenging due to nephron compensatory mechanisms and the limited sensitivity of traditional biomarkers, creating a diagnostic gap that necessitates the exploration of novel biomarkers for earlier detection. This review examines the complex pathophysiology of the disease, including renin–angiotensin–aldosterone system activation, tubulointerstitial fibrosis, and mineral metabolism disturbances. By analyzing recent scientific literature, this work evaluates current diagnostic landscape and clinical relevance of emerging biomarkers. Evidence indicates that symmetric dimethylarginine and fibroblast growth factor-23 improve detection of early metabolic and filtration changes, while urinary biomarkers like cystatin B and retinol-binding protein provide specific insights into tubular injury. Bridging the diagnostic gap requires a transition from a reactive, azotemia-based framework to a multi-parametric diagnostic approach that integrates novel biomarkers with serial clinical and laboratory monitoring. Although financial constraints and limited availability restrict widespread clinical implementation, incorporating these advances is essential for earlier prognostic stratification and timely therapeutic decision-making. This integrated strategy has the potential to slow disease progression and improve survival and quality of life in cats with chronic kidney disease.